6440774551 has 4 divisors (see below), whose sum is σ = 6648541504. Its totient is φ = 6233007600.

The previous prime is 6440774533. The next prime is 6440774569. The reversal of 6440774551 is 1554770446.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (6440774533) and next prime (6440774569).

It is a cyclic number.

It is not a de Polignac number, because 6440774551 - 2¹³ = 6440766359 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6440774498 and 6440774507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6440774591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 103883430 + ... + 103883491.

It is an arithmetic number, because the mean of its divisors is an integer number (1662135376).

Almost surely, 2^6440774551 is an apocalyptic number.

6440774551 is a deficient number, since it is larger than the sum of its proper divisors (207766953).

6440774551 is a wasteful number, since it uses less digits than its factorization.

6440774551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207766952.

The product of its (nonzero) digits is 470400, while the sum is 43.

The square root of 6440774551 is about 80254.4363322053. The cubic root of 6440774551 is about 1860.5700791391.

The spelling of 6440774551 in words is "six billion, four hundred forty million, seven hundred seventy-four thousand, five hundred fifty-one".